The Pennsylvania Department of Environmental Protection last week issued a drought watch for 15 local counties, including much of the entire region surrounding Pittsburgh. Rainfall totals are way down in much of western Pennsylvania and eastern Ohio. Allegheny County’s rainfall total was 5.5 inches below average; Beaver County’s deficit was 8.3 inches below normal and Butler’s 7 inches. The driest months, April and June, took a real toll. June’s 1.24 inches of rainfall in the Pittsburgh region was far below its normal 4.3.

On a sunny summer day last week, Butler County farmer Larry Voll looked to the weather forecast for possible rain and wondered if it would be the day. It hadn’t rained since a half-inch fell the week before, which is grim news for a farm like his near Evans City that depends on rainfall for moisture.

It had threatened several times, but the clouds never opened up. Voll and his son not only look at the forecast, but they also track weather radar in the field with his son’s smartphone.

“It either goes to Pittsburgh or goes north of us,” Voll said.

Down in Allegheny County, dairy farmer John Scott says much the same thing.

“We haven’t had the rain in our particular area,” said Scott, whose farm is in North Fayette, earlier this week. “We’ve had a very dry June and first part of July.”

What’s unusual about this summer’s weather pattern is how some parts of the region have gotten a fair amount of rain while others have stayed bone dry. That’s evident in last week’s drought watch, which the Pennsylvania Department of Environmental Protection issued for the immediate region around Pittsburgh. The drought watch covered Allegheny, Beaver, Butler, Fayette, Greene, Fayette and Washington counties. Just east of Pittsburgh, Armstrong, Indiana and Westmoreland aren’t under the watch. But Somerset County, which is further east than Westmoreland, is.

That’s not surprising this time of year, said Brad Rehak, a meteorologist at the National Weather Service office in Pittsburgh. There are county-to-county variations in rainfall in western Pennsylvania, with some areas getting more rain than others, often from thunderstorms.

“When you get into a drought, most of your rain that comes over the summer is more localized,” Rehak said. “It’s tough to pull out. You don’t have many widespread rain events during the summer months. They come either later in the fall or earlier in the spring.”

Rain that has been as close as Pittsburgh has failed to make it to the South Hills where Trax Farms in Finleyville is located. One day two weeks ago, it rained on one side of the farm but not on the other.

And farmers don’t want all the rain at once, either. Two weeks ago on Volls farm in Evans City, a cloudburst dumped a half an inch in 10 minutes, which doesn’t do much good.

“We got a little bit of it and the rest just ran off,” Voll said. “It just came too fast, too quick. We lost about 50 percent of it.”

The rain has picked up in recent days, thanks to some moisture from the West Coast skipping the parched Midwest and providing a little relief to some areas.

“A heavy thunderstorm can make a big difference in the severity of your drought,” said Susan Lynn, one of the four owners of Sand Hill Berries in Mount Pleasant. “You can be either very fortunate or very unlucky.”